As Hillary Clinton headed into her last big day of primaries — including contests in California, Montana and New Mexico — she placed an opinion piece in the San Jose Mercury News highlighting her plans for using the public lands of the West to help achieve her goal of turning the United States into a “renewable energy superpower.”

“While protecting sensitive areas where development poses too great a risk, we can accelerate our transition to a clean energy economy by increasing renewable energy generation on public lands and offshore waters tenfold within a decade,” Clinton wrote.

Clinton has been talking about clean energy and climate change since she launched her campaign. But as she establishes herself as the presumptive Democratic nominee, her plans for the country’s energy and environmental policy take new prominence.

If this was a traditional campaign, these issues might attract increasing attention in the run-up to the general election in November, given the candidates’ starkly different visions for the nation’s energy future. But Donald Trump’s propensity for insults and Clinton’s legal peril over the private e-mail account she used while she was secretary of state are likely to overshadow this and other policy discussions.

Still, the difference between the candidates on energy and environment is immense. Trump is enthusiastic about fossil fuels. He pledges to eliminate the Environmental Protection Agency, pull the U.S. out of the international climate change treaty negotiated in Paris last December, revive coal jobs and undo President Obama’s Clean Power Plan. He is dismissive about climate change and renewable energy, saying the latter still is too expensive and not ready for prime time.

Clinton is bullish on renewable power, particularly solar. Her goals include increasing solar energy 700 percent by the end of her first term and producing enough electricity from renewable sources to power every American home within 10 years of taking office.

How she plans on accomplishing this isn’t entirely clear. Many experts say that the only way to make such huge strides is by putting a price on carbon emissions. “My view is that by and large without an economy-wide carbon pricing mechanism (such as a carbon tax or a cap and trade system for carbon dioxide) most of this is very unlikely to be achievable,” says Robert Stavins, a professor of environmental economics at Harvard University.

Without such pricing, natural gas, which is cleaner-burning than coal but still emits carbon dioxide, is simply too cheap for solar and wind to compete. While renewables have gained ground in recent years, they still made up only 7 percent of the nation’s energy mix last year, compared to 33 percent for natural gas,according to the Energy Information Agency.

Getting such a tax through an obstructionist GOP-led Congress – or even a divided Congress if Democrats take back the Senate – is unlikely. So Clinton is not counting on it. “If lightning strikes, and there’s the possibility of maybe forging an agreement with Congress, I’d certainly try and take it,” John Podesta, who chairs Clinton’s campaign, said at a conference at Stanford University last month.

Instead President Clinton likely would focus her efforts vis-a-vis Congress on trying to win support for increased investments in clean energy. For instance, she wants to create a $60 billion competitive grant program to incentivize states,cities and rural communities to become leaders on clean energy. A major selling point to Congress would be the jobs that would come from these projects.

Clinton’s renewable goals would be especially difficult to reach if President Obama’s Clean Power Plan, which requires states to reduce greenhouse gas emissions, is overturned or gutted by the Supreme Court.

Amy Myers Jaffe, executive director of Energy and Sustainability at UC Davis,says she’s not troubled that Clinton’s goals for renewable power seem overly ambitious. “I’m not sure that matters; what you’re trying to do is signal the market,” Jaffe says. The federal government’s role is limited, but presidents can make a difference through the bully pulpit and pushing Congress to incentivize clean power, as it did last year by approving five-year extensions of key subsidies for renewables.

And prices for solar panels have plummeted so far that wide-scale adoption is inevitable, says Ron Durbin, executive director of the University of California Advanced Solar Technologies Institute. “Solar energy is coming and it’s here tostay.”

But even if solar and wind power capacity was added at unprecedented rates, it wouldn’t necessarily be enough, because both are intermittent power sources. To smooth out the fluctuations in generation without fossil fuels, some sort of energy storage is necessary. “I don’t think there’s any problem in being solar-heavy; it should be coupled with more government intervention to promote storage solutions,” Jaffe says.

Clinton does have a plan for expediting siting of transmission lines needed to bring renewable power to the grid. She even would create a White House transmission office to coordinate permitting on the local state and federal level.

And if communities near federal lands want renewable power, she’ll help site the solar arrays or wind turbines on public lands through a program called the“good neighbor renewable energy partnership.”

As she told an MSNBC town hall earlier this spring: “Somebody is going to be the 21st century clean energy superpower. It’s either going to be China, Germany or us. I want it to be us because there will be a lot of jobs, again, that have to be done right here in America.”

Elizabeth Shogren is High Country News’ Washington, D.C., correspondent. Follow her on Twitter: @shogrene

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